There many different kinds of runes, and many different ways to cast them. They essentially always have the same basic structure that makes them work, however.
All runes must have a source of mana, or else the rune will not work. In radial glyphs, the power source is typically the centermost circle. The power source can simply be inserted directly in the form of raw energy when the rune is first cast. Once the power is depleted, the rune typically becomes dormant and the glyphs fade away. Power can be obtained from other sources, however; an Occultist may infuse a minor draining spell into the central glyph that drains mana from the nearest soul to power its operation. Spells that do not have a set power source tend to not be as easy to create.
The power source may deplete over time, as a miniscule amount is always drained to keep the rune always checking its parameters. This causes runes to naturally fade away after some time. Runes typically do not last more than two days if left without any power renewal. Runes that drain power from another source will never fade away as long as the source continues to provide power.
Runes can be linked directly to the caster's spiritual circuit in a dangerous process known as mending. This creates a metaphysical bond between the artifical circuit the caster creates and his own. This lets the rune effectively last forever, and drain power from the caster directly. If the rune malfunctions, however, great harm can come to the caster - even death.
A power source is only useful is it has a spell to power. The spell is the meat and butter of any rune, as the end goal of a rune is to execute a spell at a later time, or perhaps to continually perform a magical procedure. The spell tends to take up one or two circles around the power source, depending on the power and complexity of the spell. Continual spells tend to be marked by an hourglass or triangle glyph.
A rune can only perform its spell when the enchanted parameters are met. How complicated or simple the conditions must be for the rune to execute is to the discretion of the caster, but one must be set or there is no rune at all.
Parameters tend to take up the majority of a rune's glyph. Indeed setting the parameters in the first place is why creating runes is almost impossible for even many experienced mages. The requirements for a rune's execution are enumerated in the form of the runic alphabet, which contains a total of 2,452 runic characters.
A rune can execute continually if described to do so. Depending on the spell attached, this may make the rune deplete in seconds.
The rifting rune teleports a target to a designated location upon being stood on. These runes tend to expire after one or two uses.
Mechanical / Chemical ButtonEdit
Upon being touched, this rune begins a mechanical or chemical reaction with a simple, miniscule spark of energy. These runes can be used to open doors, boil some chemicals, open a trapdoor, etc.
Light runes are very basic. They operate on a continual parameter and drain energy typically from insects. Few villages use runes to power their street lights; the contraptions consist of a glass jar with a rune in it, and a few bugs. The rune drains life energy from the bugs. This does not prove to be a very efficient way of providing light, however.
A rune that is triggered when someone dies. It could be used to execute a final will, or exact revenge from the grave. It is rumored an Occultist of the Tenebris Aurora once cast a rune on her husband's scalp; a clever place, since hair covers the skin. It was set to trigger if he cheated on her - lo and behold, the poor sod's head imploded a few days later.